Anorexia nervosa is a chronic illness resulting in significant morbidity and mortality, including the compromised accrual of bone mass during adolescence. Effective prevention and treatment strategies remain unclear. The proposed study focuses on the short-term and long term effects of a novel, nonpharmacologic intervention on bone markers, and the prevention of deleterious changes in bone density and strength in adolescents with AN. The Candidate's long-range career goal is to find a safe, efficacious intervention to prevent the longterm negative effects of this chronic illness on future bone health. Coupled with this goal is a desire to increase understanding of the strategies to prevent bone loss in at-risk pediatric and adolescent patients, and to elucidate the pathways that lead to skeletal deficits in these populations. The proposed career development plan includes additional training and mentorship in 4 areas critical to the Candidate's development as an independent investigator: (1) bone physiology and biomechanics; (2) advanced training in epidemiology and the statistical methods needed to analyze these longitudinal data; (3) use of novel techniques for assessment of skeletal health; and (4) further development of leadership and mentoring skills. The research plan includes 3 aims: (1) To determine the short-term effects of low magnitude mechanical stimulation (LMMS) on bone turnover in adolescents who are hospitalized for AN; (2) To determine the longterm effects of LMMS on bone geometry and bone strength in ambulatory adolescents with a ; and (3) To determine the longterm effects of LMMS on biochemical indices of bone remodeling in ambulatory adolescents with AN. The proposed career development plan will provide the training and data necessary to support an R01 application during the later years of the award period. The results of these studies will have broad-reaching clinical importance, as evidence-based treatment protocols will likely stem from these data that result in improved care achieved for adolescents and young women with this common chronic disease. Given the health care burden associated with the current epidemic of osteoporosis in the elderly, establishing effective measures to prevent bone loss during childhood and adolescence is paramount.